Ovarian Cancer Risk May Increase in Women With Irregular Menses

In 2016, it is estimated that there will be 22,280 newly diagnosed cases of ovarian cancer in the United States. Astonishing as it may seem, the lifetime risk for a woman developing ovarian cancer is 1 in 75, with a risk of death related to the disease being 1 in 100 (excluding low malignant potential tumors).¹

Researchers set out to evaluate if the risk of developing ovarian cancer would be lowered, hypothetically, by having irregular menses; however, they discovered the opposite.²

During a 50-year prospective study of 15,528 women, there was a higher incidence of women developing ovarian cancer, with 116 cases and 84 deaths due to the disease; specifically those with self-reported menstrual irregularity during their twenties. By age 70, these women experienced a 2-fold increase in ovarian cancer incidence and mortality, with a 3-fold increase in women by age 77.^{2, 3}

Histologically, of the study participants, those with high-grade serous tumors experienced a 3-fold increase in mortality unrelated to participant age.² These statistics did not include a woman’s weight nor parity. In their study, they classified women who experienced cycles of 35 days or more as having polycystic ovarian syndrome (PCOS) which accounted for approximately 13% of study participants.³

"Discovering high-risk traits like irregular menstruation gives clinicians the opportunity to potentially save lives by identifying them as early warning signs and developing strategies to reduce these women's risk of death,” said lead researcher, Barbara Cohn, PhD, MPH, Director of the Public Health Institute, Oakland, Calif. “It is notable that the 3-fold increase in risk of ovarian cancer by age 77 we observed for women with irregular/infrequent cycles in this study is equal to the increase in risk observed for women with a family history of ovarian cancer in a first-degree relative.”³

Researchers point out that these study results could lead to a better understanding of the 90% of ovarian cancers that occur in women with no family history of ovarian cancer and with no known high-risk inherited mutations."³

References:

• American Cancer Society. (2016). What are the key statistics about ovarian cancer?
• Cirillo PM, Wang ET, Cedars MI, et al. (2016). Irregular menses predicts ovarian cancer: Prospective evidence from the Child Health and Development Studies. Int J Cancer., Apr 15. doi: 10.1002/ijc.30144.
• Public Health Institute. (2016). Women with Irregular Menstrual Cycles at Increased Risk of Ovarian Cancer Death.